Deploying PYBOSSA with nginx and uwsgi¶

This section describes how to make PYBOSSA run as a service or daemon permanently in the background. This is useful if you want to run a production-ready single PYBOSSA web server.

PYBOSSA hosted servers.

Checkout Scifabric’s hosted PYBOSSA servers.

Pre-requisites:

nginx
uwsgi
supervisord
Redis and sentinel as service (with supervisord)
RQ-Scheduler and RQ-Worker as service (with supervisord)
PYBOSSA as service (with supervisord)

First steps¶

First things first, be sure that you have followed the installation guide before starting the deployment. We highly recommend installing PYBOSSA under a regular user (without any privileges) to run the PYBOSSA technology. We will refer to this user as pybossa.

Installing nginx and uwsgi¶

You have to install nginx and uwsgi on your server machine. In a Debian/Ubuntu machine you can install them running the following commands:

1	sudo apt-get install nginx

In the (virtualenv-)installation directory of pybossa, you need to install uwsgi:

1	pip install -U uwsgi

Configuring nginx and uwsgi for PYBOSSA¶

We assume you only want to run PYBOSSA on your nginx web server. If you need to run also other services on the same server, you need to modify the nginx config files!

You have to copy and adapt the following files from your local PYBOSSA installation:

contrib/nginx/pybossa
contrib/pybossa.ini

The PYBOSSA virtual host file (contrib/nginx/pybossa) has the following directives:

location / { try_files $uri @pybossa; }

location @pybossa {
    include uwsgi_params;
    uwsgi_pass unix:/tmp/pybossa.sock;
}

location  /static {

            # change that to your pybossa static directory
            alias /home/Scifabric/pybossa/pybossa/themes/default/static;

            autoindex on;
            expires max;
        }

You can specify a user and group from your machine with lower privileges to improve the security of the site. You can also use the www-data user and group name.

Once you have adapted the PATH in the alias in that file, copy it into the folder:

1	sudo cp contrib/nginx/pybossa /etc/nginx/sites-available/.

Please delete the default config in sites-enabled (do not worry there is a backup):

1	sudo rm /etc/nginx/sites-enabled/default

Enable the PYBOSSA site:

1	sudo ln -s /etc/nginx/sites-available/pybossa /etc/nginx/sites-enabled/pybossa

And restart the server:

1	sudo service nginx restart

Creating the pybossa.ini file for uwsgi¶

You have to copy the pybossa.ini.template file to pybossa.ini in your PYBOSSA installation and adapt the paths to match your configuration!

The content of this file is the following:

[uwsgi]
socket = /tmp/pybossa.sock
chmod-socket = 666
chdir = /home/pybossa/pybossa
pythonpath = ..
virtualenv = /home/pybossa/pybossa/env
module = run:app
cpu-affinity = 1
processes = 2
threads = 2
stats = /tmp/pybossa-stats.sock
buffer-size = 65535

Install supervisord¶

Supervisord is used to let PYBOSSA and its RQ system run as Daemon in the background. It shares some of the same goals of programs like launchd, daemontools, and runit.

Install it:

1	sudo apt-get install supervisor

Configure Redis and sentinel as a service with supervisord¶

First stop Redis service and all running Redis instances with:

1 2	sudo service redis-server stop killall redis-server

We want to run redis and sentinel with supervisord because supervisord is more reliable when redis crashes (which can happen when you do not have enough RAM). So we disable redis-server daemon service with:

1	sudo rm /etc/init.d/redis-server

Go to your pybossa installation directory and copy following files:

sudo cp contrib/supervisor/redis-server.conf /etc/supervisor/conf.d/
sudo cp contrib/supervisor/redis-sentinel.conf /etc/supervisor/conf.d/
sudo cp contrib/redis-supervisor/redis.conf /etc/redis/
sudo cp contrib/redis-supervisor/sentinel.conf /etc/redis/
sudo chown redis:redis /etc/redis/redis.conf
sudo chown redis:redis /etc/redis/sentinel.conf

Now we restart supervisord (please do a full stop and start as described):

1 2	sudo service supervisor stop sudo service supervisor start

To verify the installation, you can list all redis processes, and you should see a redis-server at port 6379 and redis-sentinel at port 26379:

1	ps aux \| grep redis

These two services will now run whenever the server is running (even after reboot).

Configure RQ-Scheduler and RQ-Worker to run with supervisord¶

You need to adjust the paths and user account in this two config files according to your installation. Then copy them to supervisor (do not forget to edit them):

1 2	sudo cp contrib/supervisor/rq-scheduler.conf.template /etc/supervisor/conf.d/rq-scheduler.conf sudo cp contrib/supervisor/rq-worker.conf.template /etc/supervisor/conf.d/rq-worker.conf

Restart supervisor:

1 2	sudo service supervisor stop sudo service supervisor start

Verify that the service is running. You should see a rqworker and rqscheduler instance in the console:

1	ps aux \| grep rq

Setup PYBOSSA itself¶

As we are going to run PYBOSSA via nginx, we have to remove from the settings file the HOST and PORT sections. You can also comment them:

1 2	# HOST = '0.0.0.0' # PORT = 12000

After modifying the settings file, add the full server URL where your PYBOSSA is reachable:

1 2	SERVER_NAME = mypybossa.com PORT = 80

Let PYBOSSA run as service¶

Finally, we need to let pybossa run as service. Adjust the paths and username again in this file and copy it to the supervisor config directory:

1	sudo cp contrib/supervisor/pybossa.conf.template /etc/supervisor/conf.d/pybossa.conf

Edit now the file and adjust the paths & username.

Restart supervisor:

1 2	sudo service supervisor stop sudo service supervisor start

You should have now a running PYBOSSA production web server on your nginx installation. Open your browser and check your configured domain: http://example.com.

Congratulations!

How to update the PYBOSSA service¶

Upgrading and updating PYBOSSA as service works the same as for the standalone version. Please follow instructions on the installation instructions. Once you have upgraded the code, you will need to restart all supervisor controlled services to get the changes:

1
2
3

sudo supervisorctl restart rq-scheduler
sudo supervisorctl restart rq-worker
sudo supervisorctl restart pybossa

Logs of PYBOSSA services¶

You can find logs of all PYBOSSA services in this directory:

1	cd /var/log/supervisor

Last words about Security and Scaling¶

This guide does not cover how to secure your PYBOSSA installation. As every web server, you have to make it secure (like, e.g., strong passwords, automatic Ubuntu security updates, firewall, access restrictions). Please use guides on the Internet to do so.

PYBOSSA can also be scaled horizontally to run with redundant servers and with zero downtime over many redis, DB and web servers with load balancers in between.

If you need a secure and scalable PYBOSSA installation, please contact us. We offer hosted PYBOSSA servers, and we will handle all the hosting, customization, administration and setup for you. Check our pricing page and get in touch.